This invention relates to multi-layered devices that can be used for optical printed circuit boards (PCBs), optical backplanes, passive optical networks or other optical devices that require optical array interconnections. More particularly, this invention relates to optical interconnection devices that allow light signals to be transferred from one layer to another layer through one or more stackable optical coupling elements.
Optical transmission paths are general formed of light conducting members that are arranged to intersect each other. These light conducting members, which can consist of optical fibers or optical waveguides, are generally supported on a substrate. Oftentimes the circuit boards and optical devices are stacked to form a multi-layer device. However, such multi-layer devices, although more compact then a set of unstacked single layer devices, fail to achieve the full benefit of stacking because it is difficult to directly route a light signal from one layer to another. In such stacked devices light is generally directed from one layer to another by having the light path on one layer extend to an external peripheral extension member where it is then sent to a second layer through another peripheral extension member on a second layer.
In contrast to the prior art method, of using external peripheral extension members to transfer the optical signals from one layer to another, the present invention can directly transfer a light signal from one layer of a multi-layer device to one or more layers of the multi-layer device without the need for external peripheral extension members on each of the layers of the multi-layer device. Thus, the optical interface of the present invention can be used to connect active optical devices, passive optical devices and optical waveguides without the need for external peripheral extension members to transfer the optical signals from one layer to another.